<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1">
		<title></title>
	</head>
	<style type="text/css">
		*{
			margin: 0;
			padding: 0;
		}
		div{
			height: 300px;
		}
		.left{
			width: 100px;
			float: left;
			/* opacity: 0; */
			background-color: yellow;
		}
		.right{
			overflow: hidden;
			background-color: yellowgreen;
		}
	</style>
	<body>
		<div class="left">
			left
		</div>
		<div class="right">
			right
		</div>
	</body>
</html>